Grinding machine



Jul-y 24, 1934. H, w. MILLER GRINDING MACHINE Filed June 9, 1930 6 Sheets-'Sheet l Juy 24,1934., H. W. MILLER GRINDING MACHINE Filed June 9, 1930 6 Sheets-Sheet 2 July 24, 1934. H, w, MILLER GRINDING MACHINE Filed June 9, 1930 6 SheeLS-Sheet 3 31a/manto@ gary WMZ/61 July 24, 1934. H. W. MILLER 1,967,964

GRINDING MACHINE Filed June 9, 1930 6 Sheets-Sheet 4 6,3 62 71 72 "nr-:ifm:

n, 80/ wir iiiiiiiiiillllllii 85 Zar/'jy' W M7761 Jully 24, 11934., H, vv. MILLER GRINDING MACHINE Filed June 9, 1930 6 Sheets-Sheet 5 ttor Huf Juy 24, 1934.. H. w. MILLER GRINDING MACHINE Filed June 9, 1950 6 Sheets-Sheet 6 Patented July 24, 1934 UNITED STATES PATENT oFFlcE 7 Claims.

My invention relates to grinding machines and particularly to such machines as are particularly adapted for job work involving grinding.

The object of my invention is to provide a grinding machine particularly adapted for sharpening all kinds of edge tools. A further object of my invention is to provide a machine of the class mentioned adapted for al1 kinds of job grinding both in straight and tapered work,

0 such as in making keys, splines, etc. A further and particular object of my invention is to provide a machine as mentioned which shall be constructed and equipped to grind true edges on the curved blades of a lawn mower. A further object of my invention is to provide in a lawn mower grinding machine, means for maintaining the curved blade in proper relation to the grinding element. A further object of my invention is to provide in a lawn mower sharpening ma- 2@ chine a combination whereby the mower may be sharpened without removing the rotary cutter from the assembled mower. A further object of my invention is to provide in a machine of the class mentioned, the combination of a traveling grinding element and a stationary work holder,

the latter being equipped with means for adjusting the work with relation to the grinding element so as to produce either straight or tapered Work. A further object of my invention is to provide in a machine of the class mentioned means for adjusting the work toward and from the grinding element both horizontally and vertically. A. further object of my invention is to provide a grinding machine equipped with means for adjusting the work both vertically and horizontally with relation to the grinding element without changing the angular relation of the work to the grinding element. A further object of my invention is to provide in a tool of the class mentioned means for angularly adjusting the grinding element. Other objects will appear hereinafter.

With these objects in View my invention consists generally in a suitable frame, a movable carriage equipped with a grinding element, a work holder upon which the work is supported and means for adjusting the work holder so as to present the work to the grinding element at the desired angle either for straight or for tapered work. My invention further consists in a device as mentioned equipped with means for reciprocating the carriage, a power shaft, and a connection between the power shaft and the grinding element including a clutch for throwing the grinding element into and out of Operation. My invention further consists in a device as mentioned further characterized by means whereby the work may be adjusted toward and from the grinding element either vertically or horizontally, or both vertically and horizontally and that without disturbing the angular relation of the work holder to the grinding `element. My lnvention further consists in the combination of a traveling carriage equipped with a grinding wheel, three point supporting means for a lawn mower, and means for adjusting the said means to properly present the rotary blades of the mower to the grinding Wheel. My invention further consists in a lawn mower sharpening device as mentioned, further equipped with guide members adapted to engage the blade to be sharpened upon each side of the grinding wheel to maintain the blade in proper relation to said grinding wheel. My invention further consists in a lawn mower guiding device as mentioned, so constructed and equipped that the several blades of the rotor may be readily inserted therein in sequence, and as readily removed therefrom without changing any of the adjustments of the machine. My invention further consists in various details of construction and arrangements of parts all as will be fully described hereinafter and particularly pointed out in the claims.

My invention will be more readily understood 35 by reference to the accompanying drawings forming a part of this specification and in Which- -Y Figure 1 is a front elevation of a grinding machine embodying my invention,

Fig. 2 is an end elevation thereof,

Fig. 3 is a vertical section through the traveling carriage, illustrated on an enlarged scale,

Fig. 4 is a plan view of the carriage,

Fig. 5 is a detail section on the line 5-5 of Fig. 95 3x Fig. 6 is a detail section on the line 6 of Fig. 5 upon an enlarged scale,

Fig. 7 is a detail section upon amuch enlarged scale, on the line 7 7 of Fig. 3,

Fig. 8 is a detail view illustrating the means for adjusting the main work holder, the same being a section on the line 8--8 of Fig. 9,

Fig. 9 is a front elevation of the same, a portion being shown in section,

Fig. l0 is a detail view of one portion of the lawn mower supporting device,

Fig. 11 is a section on the line 11-11 of Fig. 10,

Fig. 12 is a detail view upon an enlarged scale 110 illustrating the lawn mower sharpening portion of the device including the adjustable work holder and the blade guide,

Fig. 13 is a detail section on the line 13 of Fig. 12,

Fig. 14 is a bottom plan view of the blade Aguiding mechanism illustrated in Fig. 12 with its associated parts,

Fig. 15 is a side elevation of a modied form of blade guide, and

Fig. 16 is a bottom plan view of the same.

Referring now to the drawings 1'-1 indicate the end members of the frame of the machine. These are connected adjacent their upper ends by a pair of longitudinally disposed bars 2 2 constituting tracks or ways for the traveling carriage, which will be described hereinafter. In order to increase the rigidity of the frame the lower portions of the members 1 are connected in any suitable manner, as by tie rods 3. Extending longitudinally through the machine is a power shaft 4 equipped with a suitable belt pulley 5. Also extending longitudinally through the machine and parallel with the shaft 4 and ways 2, is a feed screw 6. The feed screw 6 and the power shaft 4 have suitable bearings inthe end frames 1 and their ends project beyond one of the side frames, where they are connected by suitable gearing.

Loosely mounted upon the projecting end of the feed screw are a pair of similar pinions 7 and 8 which are spaced apart and provided on their adjacent faces with clutch elements 9. A clutch collar 10 is feathered upon the screw shaft and is adapted to be moved into engagement with either of the clutch faces 9 to couple the pinion 7 or 8 to the screw. The adjacent projecting end of the power shaft 4 is provided with two fixed pinions 11 and 12 respectively, the first of which is in constant mesh with pinion 7 and the latter with an idler 13, the idler being in constant mesh with the pinion 8. This construction will be clearly understood by reference to Figs. 1 and 2 of the drawings. It is obvious that by this arrangement the feed screw is geared to the power shaft, and that it may be driven in opposite directions by throwing the clutch member into engagement with either the pinion '7 or the pinion 8. Means for automatically shifting this clutch member will be described hereinafter.

Slidably mounted upon the ways 2 and adapted to travel substantially the length of the machine is a carriage 14 which carries the grinding elements and their associated parts. This carriage preferably comprises a body portion 15 having a flat upper face and equipped at both front and back with a pair of bearings 16, each having an anti-friction block 17 resting upon the ways 2. the ways suitable caps 18 are provided,bolted to the under portion of the bearings 16 and having anti-friction blocks 19. 'Ihe carriage 14 is equipped with a threaded member 20 which is in constant engagement with the feed screw `6. It is obvious that the turning of the feed screw will move the carriage in either direction according to the engagement of the clutch collar 10 with the pinions 7 or 8.

In grinding, it is usually desirable that the grinding element be reciprocated with relation to the work. I have, therefore, equipped the machine with means for automatically reversing the movement of the carriage by shifting the clutch element 10. I have also provided To hold the carriage firmly uponl l means whereby the distance of travel of the carriage may be regulated to accommodate the travel of the grinding element to the size of the work. To this end, I provide a rod 21 extending from end to end of the machine and mounted in suitable brackets upon the frame members 1. This rod is adapted to be shifted longitudinally, and upon one end is secured a yoke 23 which engages the clutch collar 10.

Adjustably secured to the rod are a pair ofarms 24 which project into the path of the carriage 14. When the carriage engages one of these arms it shifts the rod 21 longitudinally, thereby shifting the clutch member 10 and reversing the direction of the feed screw. Upon engaging the other arm, the carriage again shifts the clutch and thereby automatically reverses its direction.

Depending from the forward end of the carriage body is a pair of arms 25, the lower ends of which are apertured to receive the drive shaft 4. Loosely mounted on the shaft 4 between the arms 25 is a beveled gear 26 and a. sprocket gear 27 which are spaced apart and held against their adjacent arms by a sleeve 28. Slidably mounted on the sleeve 28 is a clutch collar 29, the opposite faces of which are provided with suitable clutch faces 30 adapted to selectively engage the clutch faces on the pnion 26 and sprocket 27 respectively. Slidably secured on the shaft 4 is a key 31 which extends through the sleeve 28, Slidably couples the collar 29 to the power shaft 4. Extending transversely of the front of the carriage is a bar 32 upon which is pivotally mounted a lever 33 for shifting the collar 29 in the usual manner. It is obvious that by means of the lever 33 the clutch collar may be thrown into engagement with either the beveled gear 26 or the sprocket gear 27, thereby selectively coupling either of said elements to the power shaft for a purpose which will appear hereinafter.

Secured to the carriage body 15 is an upwardly extending bracket 34 which carries one of the grinding wheels. Extending vertically through the standard of the bracket is a shaft 35 provided with suitable bearings 36. The lower end of the shaft 35 is provided with a pinion 37 in mesh with the beveled gear 26. At the upper end of the standard of the bracket 34 is a forwardly projecting arm 38 having a depending portion 39 upon which is swiveled the grinding head 40. The grinding head is supported upon the depending portion 39 by a three point ball bearing, as illustrated in Fig. 7. The upwardly extendng flange 41 of the grinding head is "radially tapped at three points equally distant apart to receive the anti-friction balls 42 which are held in place by screws 43. The balls extend into a peripheral groove 44 in the depending portion 39 of the head. One of the screws 43 projects beyond the grinding head Iand,l is provded with a grip 45 whereby the respective ball 42 may be firmly impinged against the" depending portion 39 to lock the grinding head against rotation.

46 indicates a Vertical shaft in the forward end of the arm 38 concentric with the portion 39 and the grinding head. The upper ends of the shafts 46 and 35 are provided with pulleys 47 which are connected by a belt 48. The lower end of the shaft 46 is provided with a beveled gear 49 which meshes with a pinion 50 fixed to a shaft ,51 mounted transversely in the grinding head, one end of the shaft 51 projects beyond the grinding head and is equipped with a grinding wheel 52. 53 indicates a cap plate to cover the pulleys 47 and belt 48. This cap is omitted from Fig. 4 for clearness of illustration.

At the rear of the carriage 14 is an arm 54. This is pivotally mounted on one of the ways 2 between the rear bearings 16 of the carriage, said arm being provided with a sleeve 55 through which the member 2 extends. 56 indicates a bushing between the sleeve 55 and the way 2. The arm 54 extends rearwardly and downwardly and at its free end is provided with a transverse sleeve 57 in which is mounted a shaft 58 carrying a grinding wheel 59. The opposite end of the shaft 58 is equipped with a sprocket gear 60 which is connected by means of a sprocket chain 61 with the sprocket gear 27. 62 indicates an idler roller to maintain the chain 61 out of contact with the screw 6. It is obvious, from the above description, that by shifting the clutch collar 29 either of the grind wheels 52 or 59 may be operatively connected to the power shaft and the other disconnected therefrom.

At the forward part of the machine I have provided a work holder for holding work of general character to be operated upon by the grind wheel 52; and at the rear of the mach`ne I have provided means for supporting a lawn mower with its rotary blades in proper relation to the grinding wheel 59. Both of these work supports are so constructed and arranged that the work may be angularly adjusted with relation to the grind wheel; and also so constructed and arranged that the work may be shifted bodily toward the grind wheels either vertically or horizontally and that without changing the angular adjustment above mentioned.

The work holder at the front of the machine includes a table 62. This constitutes a fiat elongated member extending the major portion of the length of the machine and provided in its upper face with an undercut groove 63 to facilitate securing the work thereto. At substantially its center the table is swingingly mounted on a longitudinally extending cradle 64, said table and cradle being provided with co-operating ears 65 to receive a transverse pivot pin 66. The cradle 64 comprises a longitudinally extending bar having upturned ends 67 provided with trunnions 68 mounted in suitable bearings hereinafter described. Threaded through the cradle 64 and adjacent its ends, are vertical screws 69, the upper ends of which impinge against the underface of the work table. It is obvious that by means of the screws 69 the angle of the table may be adjusted longitudinally l,of the machine.

The trunnions 68 are mounted in split bearings 70 in which they are adapted to swing to adjust the inclination of the table transversely of the machine or on an axis at right angles to the pivot pin 66. These split bearings 70 are provided with flanges '7l through which extend screws 72 for clamping the bearings on the trunnions after the table has been properly adjusted. The bearings 70 are formed on blocks 73 suitably mounted at the opposite end of the machine. Upon the inner face of one or both of said blocks are bearings 74 for a worm 75 which meshes with a worm gear 76 fixed to the adjacent trunnion 68. The shaft of the worm extends forwardly and is squared as at 77 to receive a suitable tool for turning the same. It

is obvious that by means of gearing 75--76 the cradle may be turned on its trunnions to adjust the angular position of the table. With the above described construction, the work table may be adjusted to any desired angular position with relation to the grinding wheel. This is of advantage in sharpening many types of edge tools and also for grinding tapered work of various kinds.

The blocks 73 are slidably mounted upon forwardly projecting horizontally disposed slideways 78 and are each equipped with a. pinion 79 meshing with a corresponding rack 79 extending longitudinally of the respective slideways. The pinions of both blocks 73 are xed to a single shaft 80, and one end of said shaft extends beyond one of said blocks and is squared as at 8l to receive a wrench or other tool for turning the same. By turning the shaft 80 both blocks are moved simultaneously toward or from the work, and that without changing the angular position of the table with relation to the grind wheel 52. The blocks are split as indicated at 82 and provided with clamp screws 8 3 for clamping the block to the slideways 78.

The slideways 78 are formed upon vertically movable slides 84 which are mounted on vertically disposed slideways 85 xed to the front of the frame member 1. The slides 84 are provided with pinions 86 which mesh with racks 87 on the slideways 85. 88 indicate clamp screws for clamping the slides 84 to their respective slideways. The two pinions 86, one on each slide 84, are mounted upon a single shaft 89, one end of which is squared to form a wrench hold 90. With this arrangement the two slides 84 may be simultaneously raised or lowered and their movement will be uniform, so as to maintain the work holder in its proper adjusted position.

On the opposite side of the machine from the work holder above described, I provide a work holder designed to support a lawn mower so that the knives of its rotor may be ground by the grinding wheel 59 without removing the rotor from the mower. This work holder is similar to the other in regard to its vertical and horizontal adjusting means, and is also constructed so as to angularly adjust the work if necessary. Referring particularly to Figs. 7, 10 and 11, 91 indicates slides mounted on vertical slideways 92 fixed to the rear faces of frame members 1. These slides are equipped with pinions 93 which mesh with racks 94 on the slideways 92, and are simultaneously actuated by a common shaft 95, which is operated similarly to shaft 89. 96 indicates clamp screws for holding the slides 91 in vertically adjusted position.

,f The slides 91 are provided with outwardly projecting horizontal slideways 97 upon which are mounted slide blocks 98, each of said blocks having a pinion 99 meshing with a rack 100 on the respective slideway 97. A common shaft 101 for the pinions 99 is provided for actuating the same simultaneously.

Extending from one block 98 to the other, and fixed thereto, are a pair of bars 102. 'Ihese are spaced apart by end blocks 103 forming a slot 104 between the bars. Mounted on the bars 102 are a pair of standards 105 for supporting a portion of the work. Each of these standards comprises a tubular member 106 having a depending threaded stem 107 extending through the slot and upon which is threaded a nut 108 to clamp the standard into position on the bars 102. Telescoping within the tubular member 106 is a supporting member 109, the top of which is formed with a V-notch 110, into which the frame bar A of a lawn mower is adapted to rest as indicated in Fig. 12 of the drawings. The member 109 is provided with a longitudinally extending groove 111 to receive the end of a pin 112 extending through the tubular member 106 to prevent rotation of the supporting member.

y Threaded longitudinally through the stem 107 is a screw 113 which impinges against the bottom of the supporting member 109 and by means of which the height of the latter may be readily adjusted. These screws are independently operated so that when desired the necessary inclination may be given to the work supported the adjustment of the blade C to the grinding wheel 59. The block 114 is slidably mounted on a horizontal bar 116 which extends the length of the machine and which is supported at its ends by vertical rods 117, preferably depending from the upper flanges 1' of the end frame members. These supporting rods 117 are threaded as at 118 to receive nuts 119 by means of which the height of the block 114 may be adjusted. In practice the block 114 is positioned on the .bar 116 substantially midway, longitudinally, between the members 109 and is secured in position by a thumb screw 120. The rods 117 are free to swing within reasonable limits so that the device will accommodate itself to mnwers of different sizes, and also to permit ready adjustment of the various parts. In using the device to sharpen, as a lawn mower, the handle of the lawn mower is removed and the forward bar A is rested in the notches 110. The standards 105 are adjusted longitudinally of the bars 102 so as to engage the frame bar A adjacent its ends. The mower roller B is rested in the notch 115 of the block 114, which block is adjusted on its supporting rod 116 to support the roller adjacent its center. The blocks 98 are then adjusted horizontally or vertically, or-both, to bring the rotary cutting blade C in proximity relative to the grinder wheel 59. Finer adjustments are made by means of the screws 113 and the nuts 119.

In grinding the blades the carriage 14 is reciprocated as hereinbefore described, the arms 24 being adjusted to the upper positions on the rod 21 to permit the grinding wheel 59 to move the full length of the knives C.

On account of the spiral shape of the rotary blades of a mower it is necessary to provide means to maintain the grinding wheel in proper relation to the blade as the wheel is reciprocated from end to end thereof. To this end I provide a guiding device adjustably mounted on the arm 5.4 and adapted to engage the blade upon each side of the grinding wheel. Furthermore, this guiding device must be constructed so as to facilitiate the entrance of a blade into the same and its removal therefrom without changing the adjustment of the several parts of the machine. To this end I provide a pair of substantially parallel spring arms, one on each side of the grinding wheel and each provided at its end with a, gripping device into which the blade may be readily inserted. These spring arms are mounted upon a suitable head equipped with means for adjusting the relative angular position of the grippers, and said head is adjustably mounted on the arm 54. 121-121 indicate the parallel spring arms which extend on opposite sides of the grind wheel 59 and in close proximity thereto. The inner ends of the spring arms are adjustably secured to a head 122 as by bolts 123. The forward end of each spring arm is equipped with a gripping device comprising a pair of rollers 124-125. The roller 124 is conical and is pivoted directly on the spring arm 121; whereas the roller 125 is preferably cylindrical and is swingingly mounted upon a bracket xed to the arm. 126 indicates the bracket which is formed with a hollow cylindrical head 127 upon which is pivotally mounted a disk 129 having on its periphery a lug 130 carrying the roller 125. A bolt 128 holds the disk to the head. The normal position of the rollers 124 and 125 is such that the blade C is held between the faces thereof as illustrated in Fig. 12. A spring 131 in the head 127 yieldingly presses the roller 125 against the outer face of the blade.

After the mower is in position on the supports 109 and 113, the blade C is inserted between the grippers by turning the blades clockwise when viewed in the direction shown in Fig. 12. As the blade passes under the end of the spring arms 121, the resiliency of said arms permits the same to rise sufficiently to` allow the blade to pass under the arms and the rollers 124, until the blade strikes the lower end of the roller 125 which is positioned slightly below the lower portion of the roller 124. The arms then swing back into normal position gripping the blade between the rollers.

On account of the spiral shape of the blades the spring arms upon opposite sides of the grinding wheel must be adjusted to properly engage the same, it being evident that one gripl ping device must be in advance of the other. It is for this reason that the spring arms are adjustably mounted on the head; and to provide further and finer adjustment, particularly to permit the ready insertion and removal of the blade C, I provide means for angularly adjusting the spring arms. To this end, I provide a tension lever 132 for each spring arm, said lever being pivotally mounted between the lugs 133 on the head 122. One end 134 of the lever engages the under side of the spring arm 121 and an adjusting screw 135 is threaded through the other end of the lever and impinges against the head. It is obvious that by means of the screw 135 the gripper may be nicely adjusted with relation to the blade C- and grinding wheel 59 so as to permit proper operation of the same. After a blade is sharpened the rotor is turned in a clockwise direction as viewed in Fig. 12. This causes the sharpened blade to force the rollers 125 outwardly against the tension of the springs 131, permitting the blade to pass under the same, after which the roller moves back into normal position, ready to receive the next blade.

The head 122 is provided with a cylindrical stem 136 which is adjustably mounted in a receive a nut 141 thereon, which clamps the blocks 137 in adjusted position. With the various adjustments above described it is obvious that the device may be readily and nicely adjusted to accommodate mower blades of various sizes and degrees of curvature.

In Figs. 15 and 16 I have illustrated a. modied form of the guiding device. As shown therein, 142 indicates the head corresponding to head 122, and having a stem 143 thereon adapted to be inserted in block 137. 144 indicate the spring arms each of which bears a pair of gripping rollers 145-146, the former pivotally mounted directly on the ends of the spring arms. 147 indicates brackets xed to the spring arms and having a pair of parallel upwardly extending flanges 148 between which is swingingly and slidably mounted arms 149. The rear ends of the arms 149 are slotted as at 150 to receive pins 151 fixed in the flanges 148. This slot and pin construction allows for both a sliding and a pivotal movement of the arms 149. The forward edges of the anges 148 extend beyond the rollers 145 and their under edges are curved to form cam faces 152. 'Ihe forward ends of the arms 149 are provided with lugs 153 which ride on the cam faces 152, and upon which the rollers 146 are pivotally mounted. Associated with each spring arm 144 is a bracket 154,which is bent upwardly a considerable distance above the spring arms and a bolt 155 extends through the ends of the bracket and through its respective spring arm. A compression spring 156 is arranged on the bolt and interposed between the bracket and the spring arm. A nut 157 below the arm provides means for adjusting the angular position of the arms with their grippers. 158 indicates springs normally holding the arms 149 and their rollers 146 in retracted position.

I claim:

1. In a grinding machine, a supporting frame, a pair of blocks supported on said frame at substantially the ends thereof, a cradle comprising a longitudinal bar having upturned ends, trunnions on said ends mounted in said blocks, a longitudinally extending table above said cradie, cooperating ears on said cradle and table,

a pivot pin in said ears supporting said table'r on a transverse axis, vertical screws threaded through said cradle adjacent the ends thereof and. impinging against the bottom of said table, whereby the table may be angularly adjusted longitudinally of the supporting frame, and a reciprocating grinding tool on said supporting frame, substantially as described.

2. A grinding machine as set forth in claim 1 further characterized by a worm gear on one of the trunnions of said crad1e,'a worm meshing therewith, and bearings for said worm in the adjacent supporting block, substantially as described.

3. A device as set forth in claim 1 further characterized by horizontally disposed slideways upon which the cradle supporting blocks are slidably mounted, said slideways being vertically adjustable upon the supporting frame, means for simultaneously adjusting said slideways vertically and means for simultaneously adjusting said cradle supporting blocks longitudinally on the slideways, substantially as described.

4. In a device of the class described a. frame, slideways in said frame, a carriage mounted on said slideways, means for reciprocating the carriage, a bracket on said carriage having a horizontally extending arm, a tool head swiveled on said arm on a vertically disposed axis, a grinding Wheel carried by said tool head, a drive shaft mounted in said frame and gearing extending through said bracket arm and head for driving said tool and means for locking said tool head in adjusted position, substantially as described.v

arms, a bracket on said carriage having a horizontally extending arm, a tool head swiveled on said arm on a vertical axis, a vertical shaft in said bracket, beveled gearing connecting said vertical shaft and said drive shaft, a vertical stud shaft in the end of said arm, a horizontal tool shaft in said swiveled head, beveled gearing connecting said tool shaft and said stud shaft and a driving connection between said Vertical shaft and said stud shaft arranged in said horizontal arm, substantially as described.

'l'. A reciprocatory carriage for a grinding machine comprising a body portion provided with bearings for slidably mounting the same, depending arms on the carriage having bearings for a. power shaft, an arm hingedly mounted on the body to swing vertically, a tool carried by said swinging arm, anvupwardly extending bracket on the body, said bracket having a horizontally extending arm, a tool on said horizontally extending arm and means between the said depending arms on the carriage body for selectively coupling the tools to a power shaft, substantially as described.

HARRY W. MILLER. 

